98 Storage Management with DB2 for OS/390
This replaces a manual site switch process that could require more than 20
people to be present to perform their specialized tasks. Figure 30 on page 98
shows the global GDPS architecture.
Figure30. GDPSArchitecture
Implementation
GDPS is being implemented as an automation solution, using standard sysplex
and IBM 3990 Storage Control Unit functions. The base for the implementation of
a GDPS is a sysplex spread across two sites, securing diagnostic and control
capability in case of a site failure. The two sites may be up to 40 km apart.
The sysplex must be configured to be fault tolerant: this applies to the sysplex
control data sets and to the Sysplex Timer and Coupling Facilities (if used). A
fault-tolerant SysplexTimer confi guration consists of two interconnected timers,
properly connected to all processor complexesthat are par t of the sysplex.
All data requiredfor an application restart must be DASD resident. All data that is
part of the same group of applications must be in one site, andPP RCmust be
used to maintain a synchronouscopy of the data in the backup location. Spare
processor capacity and/or expendableworkload must be available in the
secondary site so that enough capacity isavailable to resume the critical
workload in the backup location.
Processing
GDPS processing is initialized based on a GDPS configuration database that
contains site and configuration details. This allows GDPS to support and
automate the routine PPRC configuration management tasks such as setting up
links and pairs, to perform an interval driven check on the current status of the
configuration and compare it against the target configuration status.
RemoteCopy
Network Site
B
Site
A
Local
DASD
Primary
DASD
40kmMax Distan ce
CF
9037-2 9037-2
HighPerformance
Routing
Secondary
DASD Local
DASD
CF